DIELECTRIC-RELAXATION IN WATER-TERT-BUTANOL MIXTURES - THE WATER-RICHREGION

Measurements of dielectric relaxation in water-tert-butanol mixtures h ave been performed by means of a frequency domain coaxial technique in the range 0.03-3 GHz, at 5-degrees-C and for an alcohol mole fraction X, ranging from 0 to 0.1. Experimental data give evidence for two rel axation processes whose relative amplitude and relaxation time depend on alcohol concentration. A two state model involving hydration and bu lk water mutually exchanging at a finite rate is used to interpret die lectric data in the water rich region (X < 0.02). An anomalous behavio r, evidenced at X almost-equal-to 0.045, is interpreted as the occurr ence of a self-aggregation process involving part of the alcohol molec ules in the solution.